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(No Model.)

G. CROSBY & E. M. FOX.

ELEGTRIG LAMP. I No. 248,407. Patented Oct. 18,1881.

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f? v I Fi NTOBI ATTORNEYS.

UNITED STATES PATENT OFFICE.

GEORGE CROSBY, OF NEW YORK, AND EDWIN M. FOX, OF BROOKLYN, ASSIGN- ORS TO THE AMERICAN ELECTRIC LIGHT COMPANY, OF NEW YORK, N. Y.

ELECTRIC LAMP.

SPECIFICATION formingpart of Letters Patent No. 248,407, dated October 18, 1881.

Application filed April 12, 1881. (No model.)

To all whom 'it mayconcern Be it known that we, GEORGE CRosBv, of New York city, and EDWIN M. FOX, of Brooklyn, in the county of Kings and State of New York, have invented a new and Improved Electric Lamp; and we do hereby declare that the following is a full, clear, and exact description of the same, reference being bad to the accompanying drawings, forming part of this speci- Io fication, in which-- 7 Figure 1 is a vertical central section of the lamp. Fig. 2 is an enlarged view, in perspective, of the carbon. Fig. 3 are correspondingly-enlarged views of the two sections of the 1 carbon. Fig. at is an enlarged detail of the device for holding the carbon.

Our invention relates to an improvement in electric lamps of that type in which an incandescent carbon or wire is made to constitute the source of light.

Our invention consists in the peculiar construction of the incandescent conductor, and in the peculiar construction of the glass globe or case, as hereinafter fully described.

2 5 In the drawings, Arepresents the glass globe, andB the non-conductingsupportfor the same, through which pass the circuitwires ab. This support B is to be made of hard vulcanized rubber or other analogous homogeneous mate- In form it consists of a central stem, 0, atablelike flange or projection, d, upon which rests the lower edge of the glass globe, and an upwardly-projecting stem and bulb, 6, through 5 which the wires emergeto connect with the carbon or incandescent body. To construct thisinsulated supporta sheetof rubberis taken and a wire placed near the edge of the same, and the sheet then rolled into a helix. As soon as this wire is properly insulated another wireis placed therein parallel to the first, and the rollin g continued until the diameter of the roll of rubber is large enough. This roll is then vulcanized and afterward placed in a lathe and 5 turned to the form shown in the drawings.

For connecting the glass globe to the insulating-stand we make the flange or table d wit-l1 a smooth upper surface, place upon the lower edge of the globe a grooved soft-rubber 5o gasket, f, then bring the lower edge of the rial which is a non-conductor of electricity.

globe against the upper face of the table (I, and exhaust the air, when the globe will be held to the table, without danger of fracture to the glass, by a pressure of fifteen pounds to the square inch. To remove the globe it is only 5 necessary to clip the teat of glass 9 at the top of the globe with a pairof pinchers, which allows the air to rush in and permits theglobe to be lifted off without trouble. The advantage of this means of introducing the wires to the globe in contradistiuction to fusing them in theglass is thatif the globe becomes broken only this is wasted, and another may be fitted to the wire connections without sacrificing the globe, wire connection,'and all. Furthermore, it permits access to the carbon to renew or readjust it withoutdestroying the globe.

Instead of having a perfectly smooth upper surface for the table or flange d, it may have a circular groove in its upper face immediately beneath the lower edge of the globe, as shown in dotted lines at 00, into which groove a ring of rubber may be placed, and upon which the lower edge of the naked globe may be fitted or embedded. 7 5

The wires a b are connected at their lower ends to metal blocks or contact-faces ab, which are partly embedded upon opposite sides of the non-conducting stem 0. These contactblocks are designed to come in contact with or 8c rest upon corresponding metal blocks or faces contained within a socket of the support (not shown) for the lamp, which corresponding blocks form in the said socket terminals for the circuit-wires, so that when the blocks a b rest upon the same the circuitis passed through the wires a I) andthe light-emitting carbon.

The carbon C, which-we use, isa peculiar one, designed to secure the uniform distribution of light from all ofits sides. It is formed of two 0 inverted-U-shaped pieces, which are fixed together in planes at right angles, as shown in Figs. 2 and 3, so as to form four pendent legs. One of the wires, a, is made to connect with two of these legs on one side, and the other wire, 5 b, is made to connect with the other two legs on the other side, so that the current passes up two of the legs, crosses over at the top, and then passes down the other two legs to pro duce uniform incandescence throughout the whole surface. This form of carbon, it will be seen, has every portion of its broad sides exposed for direct radiation outwardly, making the distribution of light unil'orm throughout a horizontal circle. In a horseshoe form of carbon its broadsides are exposed in two directions, and its thin edge in the other two, making the emanations of light of difl'erent intensity from different points, and, moreover, the inner broad-side surface of this form of carbon cannot radiate its light direct, but it is reflected and concentrated in a single spot instead of being diffused in rays emanating directly from the incandescent carbon.

With our form ofcarbon it will be seen that all of thebroad sides of the carbon radiate their rays directly from the incandescent body.

The carbon-holder we construct in the form of twojointed spring-jaws, h h, (see Fig. 4,) which form of carbon-holder permits the carbon to be quickly adjusted to the same without danger of breakage, and to be as quickly removed, the spring also allowing thejaws to yield to the expansion and contraction of the carbon.

In making use of our invention we propose, in some cases, to use a heavy cut-glass globe made with square or other lorm ot' polygonal faces, as shown in the drawings. When the globe is thus made of heavy glass the teat at the top must still be preserved relatively thin,

so as to permit the globe to be hermetically sealed by fusion after the exhaustion of the air. The object of this is to make a more brilliant display of the light by separating the beams into groups in their passage through the (lifl'erent faces. e contemplate, however, in most cases, using the plain globular form of globe or cover.

Having thus described our invention, what we claim as new is 1. The incandescent conductor for an electric lamp, consisting of broad and thin U- shaped pieces inverted and arranged as described, with their planes bisecting each other and radiating from a common center, whereby every plane surface is exposed for direct radiation of light, as described.

2. As a new article of manufacture, a heavy cut-glass globe for an electric light, made in one piece, with polygonal faces and a relatively thin teat at the top, as described.

3. The co|nbination,'with an electrical lamp, of a heavy glass globe or covering made of one piece, and having polygonal faces, and provided with a relatively thin teat at the top, as and for the purpose described.

GEORGE CROSBY. EDWIN M. FOX. Witnesses:

EDWD. W. BYRN, SoLoN G. KEMoN. 

